;
(function(w) {
    var $doc = w.document;
    w.screen = {
        // 记录文字，待增加颜色 
        log: function(msg, keep_line) {
            var dom = $doc.createElement(keep_line ? "span" : "div");
            dom.innerText = msg;
            $doc.body.appendChild(dom)
        },
        logHtml: function(html) {
            var dom = $doc.createElement("div");
            dom.innerHTML = msg;
            $doc.body.appendChild(dom)
        }
    }
})(window)